The present invention relates to methods for producing chewing gum. More particularly the invention relates to producing chewing gum containing high-potency sweeteners which have been treated to control their release and enhance shelf-life stability.
In recent years, efforts have been devoted to controlling release characteristics of various ingredients in chewing gum. Most notably, attempts have been made to delay the release of sweeteners and flavors in various chewing gum formulations to thereby lengthen the satisfactory chewing time of the gum. Delaying the release of sweeteners and flavors can also avoid an undesirable overpowering burst of sweetness or flavor during the initial chewing period. On the other hand, some ingredients have been treated so as to increase their rate of release in chewing gum.
In addition, other efforts have been directed at perfecting the use of high-potency sweeteners within the chewing gum formulation, to thereby increase the shelf-life stability of the ingredients, i.e. the protection against degradation of the high-potency sweetener over time.
A recently identified class of high potency sweeteners are N-substituted derivatives of aspartame. Some of these sweeteners may give a long lasting sweetness release when used in chewing gum, while others may give a fast release that may not be compatible with the release of flavor. By modifying N-substituted derivatives of aspartame by various methods, a controlled release from chewing gum can be more effective to balance sweetness with flavor and give a highly consumer acceptable product.
The class of N-substituted derivatives of aspartame useful in the present invention are described in U.S. Pat. No. 5,480,668. One particularly preferred N-substituted derivative of aspartame is commonly known as neotame. The chemical name of this sweetener is N-[N-(3,3-dimethylbutyl)-L-α-aspartyl]-L-phenylalanine 1-methyl ester. Other preferred N-substituted derivatives of aspartame sweeteners include two other similar chemicals, namely N-[N-[3-(4-hydroxy-3-menthoxyphenyl)propyl]-L-α-aspartyl]-L-phenylalanine 1-methyl ester and N-[N-(3-phenylpropyl)-L-α-aspartyl]-L-phenylalanine 1-methyl ester. A method for preparing neotame is disclosed in U.S. Pat. Nos. 5,510,508 and 5,728,862. Each of the foregoing patents is hereby incorporated by references.
Other patents disclose how a sweetener like aspartame can be physically modified to control its release rate in chewing gum.
For example, U.S. Pat. No. 4,597,970 to Sharma et al. teaches a process for producing an agglomerated sweetener wherein the sweetener is dispersed in a hydrophobic matrix consisting essentially of lecithin, a glyceride, and a fatty acid or wax having a melting point between 25° C. and 10° C. The method disclosed uses a spray-congealing step to form the sweetener-containing matrix into droplets, followed by a fluid-bed second coating on the agglomerated particles.
U.S. Pat. Nos. 4,515,769 and 4,386,106, both to Merrit et al., teach a two step process for preparing a delayed release flavorant for chewing gum. In this process, the flavorant is prepared in an emulsion with a hydrophilic matrix. The emulsion is dried and ground, and the resulting particles are then coated with a water-impermeable substance.
U.S. Pat. No. 4,230,687 to Sair et al. teaches a process for encasing an active ingredient to achieve gradual release of the ingredient in a product such as chewing gum. The method described involves adding the ingredient to an encapsulating material in the form of a viscous paste. High-shear mixing is used to achieve a homogeneous dispersion of the ingredient within the matrix, which is subsequently dried and ground.
U.S. Pat. No. 4,139,639 to Bahoshy et al. teaches a process of “fixing” aspartame by co-drying (by spray drying or fluid-bed coating) a solution containing aspartame and an encapsulating agent, such as gum arabic, to thereby surround and protect the aspartame in the gum during storage.
U.S. Pat. No. 4,384,004 to Cea et al. teaches a method of encapsulating aspartame with various solutions of encapsulating agents using various encapsulation techniques, such as spray drying, in order to increase the shelf-stability of the aspartame.
U.S. Pat. No. 4,634,593 to Stroz et al., teaches a method for producing controlled release sweeteners for confections, such as chewing gum. The method taught therein involves the use of an insoluble fat material which is mix mulled with the sweetener.